1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * Driver for Loongson-2K BMC IPMI interface 4 * 5 * Copyright (C) 2024-2025 Loongson Technology Corporation Limited. 6 * 7 * Authors: 8 * Chong Qiao <qiaochong@loongson.cn> 9 * Binbin Zhou <zhoubinbin@loongson.cn> 10 */ 11 12 #include <linux/bitfield.h> 13 #include <linux/ioport.h> 14 #include <linux/module.h> 15 #include <linux/types.h> 16 17 #include "ipmi_si.h" 18 19 #define LS2K_KCS_FIFO_IBFH 0x0 20 #define LS2K_KCS_FIFO_IBFT 0x1 21 #define LS2K_KCS_FIFO_OBFH 0x2 22 #define LS2K_KCS_FIFO_OBFT 0x3 23 24 /* KCS registers */ 25 #define LS2K_KCS_REG_STS 0x4 26 #define LS2K_KCS_REG_DATA_OUT 0x5 27 #define LS2K_KCS_REG_DATA_IN 0x6 28 #define LS2K_KCS_REG_CMD 0x8 29 30 #define LS2K_KCS_CMD_DATA 0xa 31 #define LS2K_KCS_VERSION 0xb 32 #define LS2K_KCS_WR_REQ 0xc 33 #define LS2K_KCS_WR_ACK 0x10 34 35 #define LS2K_KCS_STS_OBF BIT(0) 36 #define LS2K_KCS_STS_IBF BIT(1) 37 #define LS2K_KCS_STS_SMS_ATN BIT(2) 38 #define LS2K_KCS_STS_CMD BIT(3) 39 40 #define LS2K_KCS_DATA_MASK (LS2K_KCS_STS_OBF | LS2K_KCS_STS_IBF | LS2K_KCS_STS_CMD) 41 42 static bool ls2k_registered; 43 44 static unsigned char ls2k_mem_inb_v0(const struct si_sm_io *io, unsigned int offset) 45 { 46 void __iomem *addr = io->addr; 47 int reg_offset; 48 49 if (offset & BIT(0)) { 50 reg_offset = LS2K_KCS_REG_STS; 51 } else { 52 writeb(readb(addr + LS2K_KCS_REG_STS) & ~LS2K_KCS_STS_OBF, addr + LS2K_KCS_REG_STS); 53 reg_offset = LS2K_KCS_REG_DATA_OUT; 54 } 55 56 return readb(addr + reg_offset); 57 } 58 59 static unsigned char ls2k_mem_inb_v1(const struct si_sm_io *io, unsigned int offset) 60 { 61 void __iomem *addr = io->addr; 62 unsigned char inb = 0, cmd; 63 bool obf, ibf; 64 65 obf = readb(addr + LS2K_KCS_FIFO_OBFH) ^ readb(addr + LS2K_KCS_FIFO_OBFT); 66 ibf = readb(addr + LS2K_KCS_FIFO_IBFH) ^ readb(addr + LS2K_KCS_FIFO_IBFT); 67 cmd = readb(addr + LS2K_KCS_CMD_DATA); 68 69 if (offset & BIT(0)) { 70 inb = readb(addr + LS2K_KCS_REG_STS) & ~LS2K_KCS_DATA_MASK; 71 inb |= FIELD_PREP(LS2K_KCS_STS_OBF, obf) 72 | FIELD_PREP(LS2K_KCS_STS_IBF, ibf) 73 | FIELD_PREP(LS2K_KCS_STS_CMD, cmd); 74 } else { 75 inb = readb(addr + LS2K_KCS_REG_DATA_OUT); 76 writeb(readb(addr + LS2K_KCS_FIFO_OBFH), addr + LS2K_KCS_FIFO_OBFT); 77 } 78 79 return inb; 80 } 81 82 static void ls2k_mem_outb_v0(const struct si_sm_io *io, unsigned int offset, 83 unsigned char val) 84 { 85 void __iomem *addr = io->addr; 86 unsigned char sts = readb(addr + LS2K_KCS_REG_STS); 87 int reg_offset; 88 89 if (sts & LS2K_KCS_STS_IBF) 90 return; 91 92 if (offset & BIT(0)) { 93 reg_offset = LS2K_KCS_REG_CMD; 94 sts |= LS2K_KCS_STS_CMD; 95 } else { 96 reg_offset = LS2K_KCS_REG_DATA_IN; 97 sts &= ~LS2K_KCS_STS_CMD; 98 } 99 100 writew(val, addr + reg_offset); 101 writeb(sts | LS2K_KCS_STS_IBF, addr + LS2K_KCS_REG_STS); 102 writel(readl(addr + LS2K_KCS_WR_REQ) + 1, addr + LS2K_KCS_WR_REQ); 103 } 104 105 static void ls2k_mem_outb_v1(const struct si_sm_io *io, unsigned int offset, 106 unsigned char val) 107 { 108 void __iomem *addr = io->addr; 109 unsigned char ibfh, ibft; 110 int reg_offset; 111 112 ibfh = readb(addr + LS2K_KCS_FIFO_IBFH); 113 ibft = readb(addr + LS2K_KCS_FIFO_IBFT); 114 115 if (ibfh ^ ibft) 116 return; 117 118 reg_offset = (offset & BIT(0)) ? LS2K_KCS_REG_CMD : LS2K_KCS_REG_DATA_IN; 119 writew(val, addr + reg_offset); 120 121 writeb(offset & BIT(0), addr + LS2K_KCS_CMD_DATA); 122 writeb(!ibft, addr + LS2K_KCS_FIFO_IBFH); 123 writel(readl(addr + LS2K_KCS_WR_REQ) + 1, addr + LS2K_KCS_WR_REQ); 124 } 125 126 static void ls2k_mem_cleanup(struct si_sm_io *io) 127 { 128 if (io->addr) 129 iounmap(io->addr); 130 } 131 132 static int ipmi_ls2k_mem_setup(struct si_sm_io *io) 133 { 134 unsigned char version; 135 136 io->addr = ioremap(io->addr_data, io->regspacing); 137 if (!io->addr) 138 return -EIO; 139 140 version = readb(io->addr + LS2K_KCS_VERSION); 141 142 io->inputb = version ? ls2k_mem_inb_v1 : ls2k_mem_inb_v0; 143 io->outputb = version ? ls2k_mem_outb_v1 : ls2k_mem_outb_v0; 144 io->io_cleanup = ls2k_mem_cleanup; 145 146 return 0; 147 } 148 149 static int ipmi_ls2k_probe(struct platform_device *pdev) 150 { 151 struct si_sm_io io; 152 153 memset(&io, 0, sizeof(io)); 154 155 io.si_info = &ipmi_kcs_si_info; 156 io.io_setup = ipmi_ls2k_mem_setup; 157 io.addr_data = pdev->resource[0].start; 158 io.regspacing = resource_size(&pdev->resource[0]); 159 io.dev = &pdev->dev; 160 161 dev_dbg(&pdev->dev, "addr 0x%lx, spacing %d.\n", io.addr_data, io.regspacing); 162 163 return ipmi_si_add_smi(&io); 164 } 165 166 static void ipmi_ls2k_remove(struct platform_device *pdev) 167 { 168 ipmi_si_remove_by_dev(&pdev->dev); 169 } 170 171 struct platform_driver ipmi_ls2k_platform_driver = { 172 .driver = { 173 .name = "ls2k-ipmi-si", 174 }, 175 .probe = ipmi_ls2k_probe, 176 .remove = ipmi_ls2k_remove, 177 }; 178 179 void ipmi_si_ls2k_init(void) 180 { 181 platform_driver_register(&ipmi_ls2k_platform_driver); 182 ls2k_registered = true; 183 } 184 185 void ipmi_si_ls2k_shutdown(void) 186 { 187 if (ls2k_registered) 188 platform_driver_unregister(&ipmi_ls2k_platform_driver); 189 } 190